Halamphora Thumensis Guide
Credit: Josh Stepanek
  1. Valves small
  2. Valves semi-elliptical
  3. Apices capitate

Valves are small, 9-13 ┬Ám in length and broadly semi-elliptical to semi-circular. Valve apices are protracted and capitate. The raphe is straight. The axial area is narrow at the poles, widening to form a lanceolate central area. Dorsal striae are composed of a single areola.